Lubricating compositions



Patented Oct. 14, 1952 2,614,078 LUBRICATING COMPOSITIONS Leonard R. Churchill, Cranford, N. J., assignor to Tide Water Associated Oil Company, Bayonne, N. .1 a corporation of Delaware No Drawing. Application December 10, 1949, Serial No. 132,421

The present invention relates to novel lubricating compositions and to the preparation thereof.

In the field of lubrication, extensive use has been made of compositions based upon a mineral oil, or fractions thereof, blended with sulfurized substances to impart certain desired properties to such oils that enhance the performance characteristics thereof in usage as lubricants for particular requirements. In example, the art is aware of the use of sulfurized substances blended with mineral oils for improving the oil with respect to extreme pressure properties, anti-welding, oiliness, etc. Thus, such sulfurized oil compositions have found extensive usage for many and varied lubricating operations and, particularly so as cutting oils, extreme pressure lubricants, etc. The art has resorted to various means for the preparation of such lubricants and, among such means, a widely used method is to incorporate sulfur into the compositions by blending a mineral oil with a sulfurized fatty oil. Although, by proper blending thereof, compositions may be prepared that possess properties enhancing usage of the lubricant where extreme pressure properties, improved cutting qualities,

etc. are desired, such blends generally possess certain drawbacks that have retarded their more extensive usage for certain lubricating operations of specialized nature. For example,'in some lubricating operations, it is highly desired that the lubricant be light in color and transparent and, in particular, such requirements are especially desired in cutting operations wherein visibility of the cutting tool and work is required during the cutting operation. For such usages, compositions comprising mineral oils blended with sulfurized materials have a drawback in that, although the mineral oil component may per se be light in color and transparent, blends thereof with sulfurized fatty oils are either too dark in color or are of non-transparent character, or both. The reason therefor is that fatty oils, upon sulfurization, usually provide dark c01- ored and/or non-transparent products whereby, upon being blended with a mineral oil, the resulting blend possesses undesired characteristics as aforesaid for lubricating operations wherein lightness in color and transparency are desired characteristics for the lubricant. Hence, there is a need in the art for lubricating compositions based on a mineral oil blended with a sulfurized fatty oil that are light in color, transparent and stable against darkening during storage and usage while possessing the desired properties imparted to the mineral oil by blending thereof with Claims. (Cl. 25237.5)

the sulfurized fatty oil. A major object of the present invention is to provide lubricatingcornpositions that are devoid of the aforesaid undesirable characteristics generally possessed by sulfurized fatty oil-containing-mineral oil compositions.

Generally speaking, the present inventionis based upon the discovery that a mineral oil blended with a sulfurized fatty oil, and which blend is dark colored and/ or is objectionably nontransparent due to the presence of the sulfurized fatty oil therein, may be converted to suitable light colored, transparent lubricating compositions by subjecting such blends to an oxidation treatment as described more fully hereinafter.

As is apparent from the foregoing, the lubricating compositions embodied herein contain, as essential ingredients, a mineral oil possessing characteristics suitable for the contemplated usage of the composition, and a sulfurized fatty oil that, upon being blended with the mineral oil, substantially darkens the mineral oil and/or provides a blend of non-transparent character. Hence, and although it is not intended that the present invention'be limited. as to the method for preparation of the sulfurized fatty oil-mineral oil blends to be subjected to treatment in accord ance with this invention, an efiicacious method is to simply dissolve the sulfurized fatty oil, in de sired concentration, in the mineral oil by use of means such as heating, agitation, or otherwise, as desired. I I

With reference to the mineral'oil component of the compositions embodied herein, a wide range of mineral oils may be employed, the particular physical characteristics thereof being dependent upon the particular lubricating operation for which .the composition is to be employed. Hence, the invention contemplates use of mineral oils that possess lubricating properties and which 'may be derived from any of a variety of petroleum crudes including vparafiinic, naphthenic and mixed crudes. Although it is not intended that the present invention be limited to lubricants for usage in cuttin operations, the compositions contemplated herein find particular utility therefor, and hence, for purposes of illustration, the invention is described with particular reference thereto. For such cutting oil usage, the compositions contemplated herein desirably containa mineral oil that possesses lubricating properties, .a viscosity within the range of about 50 to 900 SUS at F., and a flash point of at least .300 F. More preferably, .and particularly for contem plated usage in light cutting operations, the

3 mineral oil component employed desirably possesses a viscosity of about 50 to 300 SUS at 100 F., has a flash point of over 300 F., and is light in color, e. g., having an ASTM color value of about 1 to 3 or lighter.

With reference to the second essential component of the compositions embodied herein, i. e., a sulfurized material, the invention contemplates use of fatty oils that, upon sulfurization,

are dark-colored and/or are of non-transparent character and which, upon blending. with. a

mineral oil, dark and/or impart non-transparent characteristics to the mineral oil.. Although the invention contemplates broadly the use of fatty oils that possess such characteristics upon sulfurization, suitable illustrations of such fatty oils...

include sperm oil, lard oil, and the like. Depend ing upon the particular type of fatty oil employed, the amount of sulfur combined there with may be varied but, for most purposes, sulfurized fattyoils containing aboutv 5: to; sulfur are employed; The artiistaware of various methods for-"preparation of sulfurized.v fatty oils and, hence, a detailed description thereof is;not deemed necessary herein. However, for'purposesof illustration without intent of limitation, and using sperm and. lardt oilsto illustrate specific embodiments, sulfurizationi thereof to provide substances suitable for? practicing this invention may be effected-byrpreparing a mixture of the fatty oils with, for example, about. 10% by, weight thereof of l sulfur flour, and :heating. the mixture with;agttation:at'faboutt320.'to:400 E. for about 1% t'o 2: hours.

Dependingt upon. the: intended usage of. the compositions. embodied herein; the; amount of salt urizedf f atty oil blended with the. mineral oil may. be varied over; a wide: range. Generally speaking. however, the compositions contemplatedjzhereinv comprise a. suitable mineral oil blendedi with; sulfurizedt material in. an amount mutually;- imparting: perceptible darkening of colon'whichausuallyyamounts to from about 1% toI-about 100% ,-.based1:on the' weightofthe minemll oil, of. the sulfurized fatty, oil. Thus, for certain heavy: duty 'lubricating operations and whereina high-concentration of sulfurmay be desired: in the blended composition, the. sulfurizedlfatty; oilmay berused inaratioas high as equal .partsby weight with the mineral, ,whereas, for lighter. duty lubricating. operations, the amount of sulfurized fatty oil employed is usually from-about 1%; to about. 10%, or about.1%, to about 5%,- byweight of the mineral oil. More specific I illustrations include. a. suitable mineral oil .blended with about .2150. 5 of .sulfurized, fatty 011, e. g sperm.oil or lardoil containing about 10%. of sulfur in .nonecorrosiveform.

In.-preparing .the compositions embodied herein, a-blendof themineral oil and sulfurized fatty oil, and. which blend. is. of undesirable dark..color and/or of.nontransparent character due to the presenceof thesulfuri'zed. fatty oil, is. subjected .tocacontrolled oxidation treatment to. substane ,tiallyreduce the color-.oflthe blend andto effect conversionthereof to. a transparent composition that hasenhancedutilityv for lubricating operations wherein lightness. in color and transparency offth'elubricantare desired. In accordance with this; invention, such dark-colored and/or non.- transparent blends are treated with a free ,oxygenecontaining gas, in the presence of an oxidation catalyst, until thedark-colored'and/or noni-transparentblendis substantially reduced in color. and convertedr'to a. transparent composition. Preferably," the treatment is continued until the color characteristics of the dark-colored sulfurized fatty oil-mineral blend are similar to that of the mineral oil per se. Thus, the treatment may be employed to substantially, or fully, remove the color characteristics imparted to the mineral oil by the sulfurized fatty oil while maintaining the :desiredcharacteristics imparted to'the mineral oil by the'sulfurized fatty oil and the performance thereof for lubricating operations.

In. practicing this invention, the oxidation treatment is preferably effected by blowing or otherwise. intimately. contacting the sulfurized fatty oil-mineral oil blend with a free-oxygen containing gas, examples of which include air, oxygen, mixtures thereof, etc. in the presence of a: suitable oxidation catalyst until the desired conversion of the dark-colored blend is obtained. Although .the catalysts employed may be of many and varied types of substances having catalytic properties? for; oxidation purposes, especially preferredsubstances are' metal soaps of organic acids,-,e; g., ofv fatty-acids-isuch-as.oleic, stearic, and the,- like; and.- naphthenic. acids, In more specific; embodiment, suitable. catalysts include.

oil-solublesoaps. of polyvalent metals, e; g., such as lead, cobalt, manganese, etc., and moreprefera-bly the-naphthenic acid soaps-thereof which possess activity-as-oxidation catalysts. The-catalystsmaybe 'used-in-small amounts sufficient to catalyze. the oxidation and; or" if' desired, in amounts in excessthereof. For example, larger amounts maybe desired when the catalyst, in addition to. catalyzing the oxidation treatment, alsoimparts somedesired characteristic orchar-- acteristicsto the-blend.. As. the artis aware; metalsoapspare oftentimes desired-ingredientsin.- lubricating,- compositions as. they generally impart-improvedload-carrying properties thereto. Examples of such, soaps. include suitable fatty acid andnaphthenic acid .soaps of metals and, especially, of metals such as lead, cobalt, manganesa. etc Thus, when. it. is desired to provide lubricatingcompositions embodied herein whichalso. contain .a metal soap, the metalsoaps preferably employedare thosethattalso possess activity: as oxidation catalysts. Thus, and in accordance with specific. embodiments. of. this invention, blends may be preparedthat. contain the soap. in desired proportion.e.. g., about 0.5 to.,10.% based on the. weightof'theicomposition, sufficient. to, impart,v desired properties to the blend. and, in.which.case the. soap functions. as the-catalystin the oxidation treatment and also provides lubricating. compositions, possessing desiredllproperties imparted. thereto. by such soaps and sulfurized, fattyoils.

In orderto.furtherdescribe the invention, severalj examples are. setforth hereinafter showing illustrative, but. not limitativer embodiments of the invention.

Example I Several blendswere prepared by dissolving 1% by-weight of lead naphthenatein a light-colored transparent non-viscous neutral oil having an ASTMcolOr value ofabout 2, a viscosity'oif from 50 to 60 SUS at F., a flash point of over 300 F5, and. derivedfrom a paraffinic ba'se' petrol'eum crude. Theresultingbl'ends had an ASTM color value of about'2 thus evidencing that" the'lead naphthenate'h'ad not substantially increased the color value-of the oils. Three percent by weight of a non-corrosivesulfurized'sperm' oil (10% sulfur) was dissolved in the lead naphthenatemineral oil blends "whereupon--dark-reddishblack colored blends were obtained having ASTM color values of about 5 to 5 /2. Each of the darkcoloredblends was heated to, 160 to 180 F. and treated by bubbling air 'therethrou'gh. Upon such treatment for periods of about 8 to 24 hours, during which no evidence of precipitation was observed, the dark-colored blends were reduced in colorvalue to about 2 /2, or even lighter in some 7 instances, i. e., the sulfurized fatty oil blends were reduced in color to ASTM values at least as low as that of the compositions minus the color-imparting sulfurized fatty oil.-

In order to illustrate'the importance of using an oxidation catalyst, a dark-colored composition. was prepared consisting of 97% of V a mineral oil as described in this example blended with 3% of the sulfurized sperm oil, and, hence, devoid of the oxidation catalyst. The composition was blown with air under the same conditions as the aforesaid lead naphthenate-sulfurized fatty oil-containing composition without any significant decolorization being effected upon treatment for 192 hours.

Example II A composition was prepared by blending a mineral oil, as described in Example I, with 1% of manganese naphthenate', and 3% of sulfurized sperm as described in Example I. Upon treatment of the resulting dark-colored blend, in a manner similar to that described in Example I, the blend was reduced in colorto substantially the same color value as the mineral oil itself.

Example III A composition was prepared by blending a mineral oil, as described in Example I, with 1% of lead ,naphthenate and 3% of non-corrosive sulfurized lard oil (10% sulfur). The resulting blend, reddish-black in color, was treated with air. in the manner described in Example I, and similar thereto, the dark-colored blendwas reduced in color to substantially the same color value of the mineral oil itself.

The light-colored transparent compositions embodied herein, resulting from treatment of dark-colored sulfurized fatty oil-mineral oil blends as aforedescribed, are highly stable against reversion to dark-colored compositions as observance of the treated compositions over extended periods of time, e. g., two weeks or more, has revealed that no significant, if any, color changes occurred. Moreover, and in addition to effecting the desired conversion to lightcolored, transparent compositions, treatment of the sulfurized fatty oil-mineral oil blends in accordance with this invention generally improves the wetting properties of the blends and, as those in the art are aware, such an improvement is highly desired in lubricating compositions, especially in the use thereof for metal cutting and extreme pressure lubricating operations.

Although the foregoing examples illustratively set forth the improvements obtained by practicing this invention with reference to compositions of certain specific ingredient concentrations, it should be understood that the invention is not to be considered as limited thereto with respect to ingredient concentrations, treatment conditions, etc. As to ingredient concentrations, these may be varied over rather wide ranges as described hereinbefore. With reference to the treatment, and especially the time period necessary for reducing the color of the sulfurized fatty oil-containing blends to desired color values, the time required is dependent upon considerationof several factors including particular concen trations of ingredients employed, the desired reduction in color value, the amount of free-oxygen-containing gas maintained in contact with the blend under treatment, the extent to which agitation of the blend is maintained during the treatment to effect intimate contact of the blend with the free-oxygen-containi'ng gas, and the like. It is apparent, therefor, that the present invention in generic aspect relates to controlled oxidation of the dark-colored sulfurized fatty oil-containing mineral oil compositions in the presence of a suitable oxidation catalyst for a period of time sufficient to' effect conversion of the dark-colored blends to light-colored, trans-" parent compositions. i

As far as I am aware, bodied herein are not only novel but are the result of the use of a treatment for dark-colored sulfurized fatty oil-mineral oil blends that, in an unexpected manner, effects conversion of non-transparent blends to light-colored, transparent composisuch dark-colored and/or tions. Although the reasons underlying theresults obtained by practice of this invention are not fully understoodit appears that by use of mineral oil, blends of the sulfurized fatty oils," the controlled treatment disclosed functions to selectively oxidize and substantially reduce the color characteristics of color-impartingcomponents of the sulfurized fatty oils. An importantobservation made during the investigation upon which the present invention is based is that by sults have been provided without formationlof precipitates during the treament, thus indicating that selective oxidation of color-imparting bodies of the sulfurized fatty oils apparently occurs rather than undesired reactions between ingredients in the compositions to the extent of formation of insoluble reaction products that would tend to precipiate during the oxidation treatment.

Obviously, many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof and, therefore, only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. In the preparation of lubricating compositions by blending a mineral oil with a sulfurized fatty oil that substantially increases the color characteristics of said mineral oil, the improvement which comprises subjecting said blend to controlled contact with a free-oxygen containing gas in the presence of a metal salt of an organic acid possessing activity as an oxidation catalyst for a period of time sufficient to substantially decrease the color characteristics imparted to said blend by said sulfurized fatty oil.

2. A method, as defined in claim 1, wherein the free oxygen-containing gas is a member from the group consisting of air and oxygen.

3. In the preparation of lubricating compositions by blending a mineral oil with a sulfurized fatty oil that substantially increases the color characteristics of said mineral oil, the improvethe compositions emaeu orra ment, which: comprises subjecting said. blend. in.

controlled; contact with. a. gas. from. thegroup,

consisting off air; and:. oxygen in the: presence. of.

a. metal soap. from. thegroup consisting; of. polyvalentmetalsoaps; of. fatty acids and naphthenic.

acids possessing activity; asoxidation catalysts for. a. period; of; time suflicientz. to. substantially;

istics, of: mineral; oil: compositionshaving dis-- solvedtherein asulfurized: fatty oil that-sub.

stantially, increases-the color; characteristics of. said mineral oil which comprisessubjecting said. sulfurizedfatty oil-.containing mineral oil-.com-

position to-controlled contact. with a free-oxygen containing gasin the-presence. of a metalv salt. of an organicacid possessing activity, as an oxidation catalyst. for aperiod, of timesuiiicient to.

substantially. reduceethe color. characteristics .im-

Darted to said. composition by. said sulfurizedfatty, 011..

7. As anew composition, a.mineral.oilblended with a sulfurized fatty, oil; that. substantially increases the color characteristics of,-, said mineral oil, and which blend hasheensubjectedto. controlled contactwitha free oxygen-containing. as. in .thepresenceofa metal salt of an-organic acid possessing-activity asan oxidation catalyst for. a,

period of: time.v sufficient. to. substantially reduce. the color-characteristics.imparted.to, aid mine eral,oil by said sulfurizedfatty, oil.

8. A composition, definedinclaim. ,7, where-.- in. the; free; oxygen-containing gas is a member from the. groupconsistin of, air. and oxygen.

9. A composition, as defined inclaim 7, Wherein. the. sulfurized fatty. oil .is. sulfurized. lard, oil.

10. A composition, as defined in claim 7', whereinthe oxidationcatalyst. is apolyvalent metal soap ofan acid from. the group. consisting offatty acids. and naphthenic acids.

11. Anomposition, as defined in claim.7, where in the-sulfurized. fatty oil is sulfurized sperm, oil..

12: Acompositiomas-defined.inclaim 7, which. comprises a. mineral; oi1.in. major amount based. on; the weight .of said composition.

13. A composition, as defined in. claim. 12, wherein the. sulfurized. fatty oil. is sulfurized sperm'oil and the catalystisanaphthenic acicl saltv of a metal from. the group consisting of. lead, manganese. and cobalt,

14. As anew composition, a mineral oil blended witha sulfurized fatty, oil that substantially, in.- creases, the. color characteristics. of. saidmineral oil, and which blend has been. subjected to con-, trolled contact with. a. free. oxygen-containi'ng' gas. in thepresenceof a.naphthenic acid soap of. a metal. from. the.=gr.oup. consisting; of lead, manganese, and cobaltiora Deriodof time sufficient. to substantially, reduce. the. colorchat.- acteristicsimpartedto said. mineral oil by said' sulfurized fatty oil..

15. A composition comprising a. mineral oil in major. amountbased upon, the weight ofsaid composition, a.sulfurized fatty, oil in an amount sufficient tosubstantially increase the color char,- acteristics of said mineral oil, and a small amount of an oil-soluble metal salt of naphthenic acid that possesses activity as an oxidation catalyst, said composition being characterizedby having been subjected to controlled contactwith .a.free.- oxygen containing gas for. a period oftimesufficient to substantially decrease the. color char.- acteristics imparted thereto. by said sulfurized' fatty oil.

LEONARD R. CHURCHILL.

REFERENCES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date.

2,023,768 Otto Dec..10, 1935 2,070,567. Adams -.Feb..16, 1937 2,179,060 Smith Nov. 7, 1939' 2,240,054 Richardson .Apr. 29,1941 2,301,794 Proell et al Nov. 10,1942 

1. IN THE PREPARATION OF LUBRICATING COMPOSITIONS BY BLENDING A MINERAL OIL WITH A SULFURIZED FATTY OIL THAT SUBSTANTIALLY INCREASES THE COLOR CHARACTERISTICS OF SAID MINERAL OIL, THE IMPROVEMENT WHICH COMPRISES SUBJECTING SAID BLEND TO CONTROLLED CONTACT WITH A FREE-OXYGEN CONTAINING GAS IN THE PRESENCE OF A METAL SALT OF AN ORGANIC ACID POSSESSING ACTIVITY AS AN OXIDATION CATALYST FOR A PERIOD OF TIME SUFFICIENT TO SUBSTANTIALLY DECREASE THE COLOR CHARACTERISTICS IMPARTED TO SAID BLEND BY SAID SULFURIZED FATTY OIL. 